Photographic materials for the silver dyestuff bleaching process



United States Patent M 3,264,109 PHOTOGRAPHIC MATERIALS FGR THE SILVER DYESTIUFF BLEACHHNG PRQCESS Walter Anderan, Aescli, Basel-Land, Switzerland, assignor to Cilia Limited, Basel, Switzerland, a Swiss company No Drawing. Filed Oct. 25, 1962, Ser. No. 233,154 Claims priority, application Switzerland, Nov. 2, 1961, 12,7 05 6 1 5 Claims. (Cl. 96-99) In photographic reproduction processes, yellow dyestuffs for gelatine layers are used not only as ground colors in the composition of the layers, but also as filter dyestuffs. The dyestuifs used in the silver dyestufl bleaching process must possess a wide range of properties. In general, but especially in the case of images viewed in incident light, a good fastness to light is required as well a good bleachability in the silver dyestufi bleaching bath. It is of advantage if the solubility in Water is good so as to facilitate preparation of the layers, but, on the other hand, a high degree of diffusion resistance is required. If the yellow dyestuff is used as an image dyestuff, it should absorb light in the wavelength range of 400 to to 480 Inn, and should be highly transparent in the remaining spectrum range.

A yellow dyestuff can only be used as a filter dyestufr in the silver dyestuff bleaching process if the filter layer contains sufiicient preexposed silver bromide to ensure that the yellow in the dyestufi bleaching bath is completely bleached out. The absorption range for such filter dyestuffs can be 400 to 500 mg, or even up to 5120 m This invention is based on the observation that these requirements are especially well met by a group of yellow dyestuifs exemplified by the dyestufi of the formula HOsS 3,264,1fl9 Patented August 2, 1966 The aminobenzene sulfonic acids or aminonaphthalene sulfonic acids serving as diazo components contain at least two sulfonic acid groups and advantageously no other substituents or, at most a methyl group. The radical R in such disulfonic acids corresponds, for example, to the formula -(C 'I I )('-S=O H) in which p represents an integer not greater than 2, that is to say, 1 or 2. Aminonaphthalene disulfonic acids are preferably used. As examples of diazo components there may be mentioned:

l-aminobenzene-Z 4-disulfonic acid, 1aminobenzene-2:S-disulfonic acid, l-amino-2-methyl-3 :S-disulfonic acid, l-aminonaphthalene-3 6-disulfonic acid, and 1-aminonaphthalene-3 :6: 8-trisulfonic acid.

The dyestuils of the Formula 2 in which the radical R represent the radical of Z-aminonaphthalenet: 8-disulfonic acid have proved to be especially valuable.

In addition to the amino group, the coupling components of the formula HR -NH used in the preparation of the aminoazo dyestuffs of the Formula 3 may also advantageously contain one or two alkyl and/ or alkoxy groups containing one or two carbon atoms. There may be mentioned, for example, aminobenzene, 1-amino-2- or advantageously -3-rnethylbenezene, l-amino-2- or -3-methoxybenzene, l-amino-Q- or -3-ethylbenzene, l-amino ZzS- or -3:5 dimethylbenzene, 1 arnino-2-rnethox.y-5-methylbenzene, and 1-amin0-2:S-dimethoxybenzene.

For acylation of the aminoazo dyestuffs of the formula R N=N--R -NH so obtained there is used, for example, rneta-nitrobenzoyl chloride or advantageously a para-nitrobenzoylchloride, such as 3-n1ethyl-4-nitrobenzoyl SOzH O 1 H3 C C Ha SIOBI'I The present invention thus provides photographic materials for the silver dyestuif bleaching process that contain on a support a layer having at least one dyestuff of the formula radical that contains at least two sulfonic acid groups, R represents a benzene radical bound to the N=N-- and --N H-- groups in para-position, R represents a benzene 5 radical bound to the OC- and -Nl-I groups in metaor para-position, and X represents the radical of a dibasic acid that contains carbon.

The dyestuffs of the Formula 2 can be prepared in the known manner linking two molecules of an aminoazo dyestuff of the formula (3 R N=N--R =NH-OC-R 1NH in which R R and R have the meanings given above, by means of halides, especially the chlorides, of dibasic acids that contain carbon. The aminoazo dyestuffs of the Formula 3 are obtained when a diazo compound of an aminobenzene disulfonic acid or an aminonaphthalene disulfonic acid (R -NH is coupled with an aminobenzene (H-R -NH capable of coupling in para-position to the amino group, the resulting dyestuit is acylated with a nitrobenzoyl chloride and the nitro group is reduced to an amino group.

chloride or preferably 4-nitrobenzoyl chloride which is not further substituted.

From the nitroazo dyestuffs so prepared the aminoazo dyestufis of the Formula 3 are obtained by reduction, and these are then reacted with halides or dihasic acids that contain carbon. For this purpose there are used, for example, the dihalides of aromatic, hete-rocyclic or aliphatic dicarboxylic acids. The dihalides of cyclic dicarboxylic acids advantageously contain only a single ring. As examples there may be mentioned the dichlorides of the following acids:

Furnaric acid,

Butadiene dicarboxylic acid-(1:4),

Isophthalic acid,

Terephthalic acid,

Pyridine-2:4, -2:5-, -2:6- or 3:5-dicarboxylic acid, Pyrrol-2 S-dicarboxylic acid,

Furane-Z S-dicarboxylic acid, and

Thiophene-2 S-dicarboxylic acid.

Compounds that have proved especially valuable are the urea derivatives of the Formula 2, in which X- represents a -CO- group, obtained from the aminoazo dyestuffs of the Formula 3 by reaction. with phosgene, i.e. the dichloride of carbonic acid.

The preparation of the aminoazo dyestuif of the Formula 3 from the aforesaid starting materials by azocoupling, acylation, and reduction of the nitro groups and the linking of the amino groups by means of dicarboxylic acid dichlorides to form the dicai'boxylic acid diamides, or by means of phosgene to form the urea of the Formula 2 can be carried out in known manner.

Likewise, the photographic layers that in accordance with the invention contain at least one dyestutf of the Formula 2, can also be prepared in known manner and used for the production of colored images.

In particular, the dyestuffs of the Formula 2 can be (2) Washing in water for 3 minutes.

(3) Fixation for minutes in a solution of 200 g. of sodium thiosulfate and 20 g. of potassium metabisulfite in 1 liter water.

(4) Washing in water for 5 minutes.

(5) Hardening for 5 minutes in an aqueous formaldehyde solution of 4% strength.

(6) Washing in water for 5 minutes.

(7) Bleaching of the color image for to 20 minutes present in multi-layer material that, on a layer support, 10 with a solution containing, per liter of water, 60 to 100 g. contains a selectively red-sensitized silver bromide emulof potassium bromide, 40 to 75 g. of thiourea, 35 to 80 g. sion colored with a green blue dyestuff, and above that, a of hydrochloric acid of 30% strength and 0.001 g. of selectively green-sensitized silver bromide emulsion a-minohydroxyphenazine. colored with a magenta dyestuff and, finally, above that, (8) Washing in water \for 10 minutes. a selective blue-sensitized layer colored yellow with a dye- (9) Bleaching the residual silver tfor 10 minutes with stuff of the Formula 2. a solution containing, per liter of water, 60 g. of copper A special advantage of the dyestufis of the Formula 2 sulfate, 80 g. of potassium bromide and 15 g. of hydrois that they are highly resistant to acidic oxidation baths, chloride acid or 30% strength. for example, a bath that contains 5 g. of potassium bi (10) Washing in water for 5 minutes. chromate and 5 cc. of concentrated sulfuric acid per liter FiXatiOn for 5 nute as described under 3. of water, which is necessary when, in the course of the de- (12) Washing in water for 10 minutes. veloping process, a silver dissolving bath is required for After drying, there is obtained a yellow component the layers (reversal process), image. This yellow image layer can also be one of the Unless otherwise stated, the parts and percentages in the three layers of a multi-colored material that contains following examples are by weight: as other image-forming layers that can be bleached a cyan layer sensitized to red and a magenta layer sensi- Example 1 tized to green in the usual order. 4 grams of the dyestufi of the Formula 1 are dissolved The dyestuffs in the yellow layers so prepared and in 800 cc. of water, and 12 cc. of a saponm solution of developed are distinguished by a high fastness to light, 8% strength added to the solution so obtained. The and the colorless bleached layer areas are distinguished whole is then added to 1 kg. of a silver bromide gelatine by great purity and no yellowing is to be observed on emulsion containing 30 to g. silver in the form of prolonged exposure. silver bromide. The mixture is then homogenized, de- Instead of the dyestuif of the Formula 1 there can also aerated and cast on a suitable support, for example, a be used the yellow dyestufi's obtained form the intermedicellulose acetate film. After drying, the layer is exposed 35 ate products given in the following table, when the aminothrough a yellow separation image and then processed as monoazo dyestuff obtained from a diazo component listed follows: in Column I and a coupling component listed in Column (1) Development of the silver lmage for 8 minutes at 11 is acylated with an acid chloride listed in Column III, 20 C. in a bath contairnng, per 1000 cc. of water, 0.75 g. the nitro group reduced to form an amino group, and two of N-methylaraaminophenol, 3 g. of hydroquinone, 25 40 molecular proportions of the aminoacylaminoazo dyeg. of sodium sulfite, 40 g. of sodium carbonate and 1 g. stuff are linked through the amino groups with the aid of potassium bromide. of an acid dichloride listed in Column IV.

TABLE No. I. Diazo component II. Coupling component III. Acylating agent containing IV. Acylating agent for linkage nitro group H033 0-CH3 1 1n0--mn N1n 01o C--NO2 01o 0-6-0001 i 0100 N 2 NH: N1n 0100-Q-N0. :3

Hao o H 0001 s on-1 (IJHB CIIZ OH H0 8 (I) 3 -N1-r. NII C1OC-NO1 01-0-01 8031i Hot? 4 -NH2 ONE: o10o-1vo l H3C-O CH3 C COCI I N 80311 TABLECon-tinued No. I. Diazo component II. Coupling component III, Aeylating agent containing IV. Acylating agent for linkage nitro group 1103 s o-cm -NH1 -NH: 010 0-0 010 0-6-0 001 l SOaH H0 18 ITIH: (|)CH: e Own 010 C-NO; c100- ooo1 l H033 SOJH s OnI )-cm 7 O-NH, O-Nm c1oc -No, c1-r :c1

l I Hogs H30 17H: (I -CH3 s QNH, 010 C-C -NO1 o1-( :-o1

l H03S S0;H Hi0 w 9 -NH, 010 C-O -NO c1 -o1 HOsS- -S0.3H HaC-O i 10 ONE: C10C- NO; 0145-01 O HO3S- -503H H3O H0213 11 NH, O-am, c10o--no1 014 -01 l HQCO l SOaH As has already been stated, the dyestufis of the Formula 2 can, in general, be prepared by the known methods given above. For the sake of completeness a detailed manufacturing prescription for the dyestutf of the Formula 1 is appended: 61 parts of the sodium salt of Z-aminonaphthalene-4:8-disulfonic acid are dissolved in 1200 parts of water and the solution cooled to 0 C. with ice. The solution is acidified with 65 parts of concentrated hydrochloric acid, and 50 parts of an aqueous solution of 14 parts of sodium nitrite are added in the course of 10 minutes. The diazotization is complete after a short period, whereupon there are added 24 parts of l-amino-3- methyl'benzene which have been dissolved in 200 parts of water containing 30 parts of concentrated hydrochloric acid. After 10 minutes there are added 30 parts of crystallized sodium acetate in portions, and the whole is stirred for 24 hours at 8 to C. The reaction mixture is then heated to 70 C., 500 parts of concentrated hydrochloric acid are added, and the mixture is then allowed to cool to C. The dyestuff precipitatesin the form of a violet black powder. The dyestuif is filtered off and dissolved in 2000 parts of water having a temperature of 85 C., and sodium carbonate is added until a slightly alkaline reaction is obtained. 33 parts of anhydrous sodium acetate are then added followed by 38 parts of finely powdered 4-nitro-benzoyl chloride. The whole is then stirred for 2 hours at C. and then 15 to 20 parts of anhydrous sodium carbonate and 300 parts of sodium chloride are added; the nitrobenzoylated dyestutf precipitates and is isolated by filtration. The dyestuff so obtained is suspended in 2000 parts of water having a temperature of 40 C., and to the suspension are added 26 parts of sodium sulfide in the form of an aqueous solution, and the whole is stirred for 2 hours at 40 to 42 C. The dyestuif is precipitated with 250 parts of sodium chloride and then filtered oil at 20 C. The dyestulf is again dissolved in 3000 parts of water having a temperature of 40 C. and to the solution so obtained are added 80 parts of sodium borate. Phosgene is then introduced slowly at 40 to 45 C. unitl a Congo acid reaction is obtained. The solution is then neutralized with about 20 parts of sodium hydroxide solution of 40% Example 2 4 grams of the dyestuif of the formula HOsIS o-orn I HOsS HaC-O are dissolved in 600 cc. of hot water, and the solution so obtained is added, at 45 C., to 1 kg. of a silver halide emulsion containing 15 to 35 g. silver, if desired, in the form of a pre-exposed silver halide. This mixture can be used as a yellow filter layer.

If this filter layer contains pre-exposed silver halide, the silver halide is reduced to silver in the developing bath (No. 1 of Example 1), and the filter yellow is bleached in a subsequent silver dyestufif bleaching bath (No. 7 of Example 1).

In material to be used for the reversal process, the silver halide in the yellow filter layer must not be preexposed since it is exposed during the second exposure of the material.

Example 3 4 grams of the dyestufi of the Formula 1 are dissolved in 800 cc. of water, and the solution so obtained is added to 1 kg. of a silver bromide gelatine emulsion. After the layer, which can also form a component image of a three-layer material, has been cast and dried it is exposed under a color negative, the yellow component image of which determines the yellow image formed within the positive material.

This yellow component image is then developed with a developing solution, the composition of which is given in No. 1 of Example 1, and is then washed with water. The resulting image silver is removed in the form of silver sulfate by means of a bath that contains 5 cc. of concentrated sulfuric acid and 5 g. of potassium bichromate per liter of water. It can thus no longer have a reducing action in the subsequent silver dyestuff bleaching process. The layer is then washed with water and subjected to total exposure in a strong white light. All the residual silver halide is exposed and bleached in a developing process and a subsequent silver dyestutf bleaching process as described in Example 1, Nos. 1 to 12. A positive yellow component image is obtained.

What is claimed is:

1. Photographic material suitable for use in the silver dyestuff bleaching process, which contains on a support a gelatine silver halide layer containing at least one dyestuff of the formula I H W W H in which R represents a member selected from the group consisting of the radicals of the formulae S 03H S 0 all C H: S 0311 S 0 3H HOaS SOaH

selected from the group consisting of the radicals of the formulae SOaH and

n a t -o, o 0-. 0:

1 I o o H 0 and .C C II j ll o N o 2. Photographic material suitable for use in the silver dyestuff bleaching process, which contains on a support a gelatine-silver halide layer containing at least one dyestulf of the formula in which R represents a benzene radical bound to the N:N and -NH groups in paraposition.

3. Photographic material suitable for use in the silver dyestuff bleaching process, which contains on a support a gelatine-silver halide layer containing the dyestufl of the formula 3,264,109 9 10 4. Photographic material suitable for use in the silver dyestulf bleaching process, which contains on a support a gelatine-silver halide layer containing the dyestuff of the formula SOaH H038 5. Photographic material suitable for use in the silver dyestuff bleaching process, which contains on a support a gelatine-silver halide layer containing the dyestufr of the formula H O 318 S 0 311 O HsCO O-GHa S 0 3H H 0 38 References Cited by the Examiner UNITED STATES PATENTS 1,750,067 5/1930 Stusser 260--175 2,294,892 9/1942 Carroll et a1. 9699 2,304,884 12/1942 Carroll 9699 2,341,791 2/1944 Kaiser 260-475 2,418,624 4/1947 Chechak et a1. 9699 FOREIGN PATENTS 841,300 7/1960 Great Britain.

OTHER REFERENCES Cornwell-Clyne: Colour Cineamatography, page 420, Chapman and Hall, Ltd., 37 Essex Street, London (1951).

NORMAN G. TORCHIN, Primary Examiner.

J. T. BROWN, Assistant Examiner. 

1. PHOTOGRAPHIC MATERIAL SUITABLE FOR USE IN THE SILVER DYESTUFF BLEACHING PROCESS, WHICH CONTAINS ON A SUPPORT A GELATINE SILVER HALIDE LAYER CONTAINING AT LEAST ONE DYESTUFF OF THE FORMULA 